Thanks for your comments and your feedback. You’re right till version 3.0.9 it wasn’t possible to set multiple custom types because they were not being converted into arrays when multiple values were passed.

I’ve fixed that, it’s now possible to set multiple types as you expected. I’ve just uploaded the new version so it will be available in 15 minutes or so, until the new version has been pushed you can check out version 3.1 working here: Custom Post Types.

Once you’ve update to the new version please let me know what do you think. I’m marking this topic as resolved, feel free to change that if you encounter any problem.

Feature request (If you have a lot of time 🙂 ) :
standard placeholder/image to be set per CPT

For instance, forumposts typically don’t have featured images. Would be cool if we could either suppress thumbnails for certain CPT’s, or select a placeholder URL to for example an image stating “FORUM POST” …

FYI wpprogrammeurs.nl, you have the thumbnail_filler option which displays a placeholder when thumbnails are not present. Just use: [nlposts cpt=mycpt thumbnail=true thumbnail_filler=placeholder] (this takes the title and puts it inside the placeholder).